a question about ffmpeg and desktop video and sound capture

ok trying to get a good video and sound desktop capture with this

Code:

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ffmpeg -f alsa -ac 2  -ab 128k  -i hw:0,0 -f x11grab -s $(xwininfo -root | grep 'geometry' | awk '{print $2;}') -r 30 -qscale 1  -i :0.0  -f avi ./Desktop/mydesktop.avi

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and perfect image/video capture but the sound does not play back


any ideas why not? got some of the ideas from here

i am using an alpha lexicon box for my sound system-wide on my machine

Hi
The tutorial that you used only describes how to capture video.
There's a better tutorial here:-http://ubuntuforums.org/showthread.php?t=1392026
It captures raw video and pcm audio which is very easy to convert afterwards.
It works OK for me.
You'll probably get support there if you need help.

Quote:

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Originally Posted by ron999

Hi
The tutorial that you used only describes how to capture video.
There's a better tutorial here:-http://ubuntuforums.org/showthread.php?t=1392026
It captures raw video and pcm audio which is very easy to convert afterwards.
It works OK for me.
You'll probably get support there if you need help.

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cheers Ron will check that


it really works it is a great guide/tip

i modified it slightly so it leaves the recorded video file on desktop

Code:

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ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1024x768 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0 ./Desktop/mydesktop.mkv

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and for a good webcam plus voice grab



with help from Verb


i use this which really roks too

Code:

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ffmpeg -f alsa -ac 2 -i pulse  -f video4linux2 -i /dev/video0 -acodec pcm_s16le  -vpre lossless_ultrafast -threads 0 -s 320x240  -r 30    ./Desktop/mywebcam.avi

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AND just record your voice with a microphone to a wave file

Code:

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ffmpeg -f alsa -ac 2 -i pulse  -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0  -y  ./Desktop/myVOICE.wav

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AND just record your voice with a microphone to an alac file

Code:

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ffmpeg -f alsa -ac 2 -i pulse -acodec alac  -y ./Desktop/RecordingMYvoice.m4a

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to flac

Code:

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ffmpeg -f alsa -ac 2 -i pulse -acodec flac  -y ./Desktop/RecordingMYvoice.flac

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to aac

Code:

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ffmpeg -f alsa -ac 2 -i pulse -acodec aac -strict experimental -ab 399k  -y ./Desktop/RecordingMYvoice.aac

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---deleted---

also if you wish for an HD 1080p grab of desktop + microphone recording


having made sure your system/nvidia settings are set on 1920x1080

ie system/admin/nvdia X server settings /resolution/pick 1920/apply



run

Code:

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ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 35 -s hd1080 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0  -y  ./Desktop/Mydesktop.mkv

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if you want to grab your desktop and desktop sound (music/video) instead

use the same code line

Code:

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ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1280x1024 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0  -y ./Desktop/mydesktop.mkv

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but to make sure your mike is not picked up instead you need to do this

Quote:

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+ Q: How can I control PulseAudio input? (e.g. capture application audio instead of mic)
A: Install “pavucontrol“. Start recording with ffmpeg. Start pavucontrol. Go to the “Recording” tab and you’ll find ffmpeg listed there. Change audio capture from “Internal Audio Analog Stereo” to “Monitor of Internal Audio Analog Stereo“.
Now it should record system and application audio instead of microphone.

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Code:

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sudo apt-get install pavucontrol

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from verb

I used f.e. this command

Code:

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ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1024x768 -i :0.0 -acodec pcm_s16le -vcodec libx264 -vpre lossless_ultrafast -threads 0 1.mkv

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But I've got audio delay in recorded video in about 2sec. What I have to put in this command that audio delay disappeared?